Twenty and the Beast - Manhwa

Entering her third year in the workforce, Aya is thrilled to welcome her first junior colleague, Yamato. Despite being six years her senior, Yamato has a refreshing and caring demeanor that has made him popular with their department's colleagues. However, he also enjoys teasing and playfully bullying Aya, even though she was supposed to be training him. Whenever Yamato's intelligent and mature side shines, Aya becomes flustered. This may become a problem if she can't focus on her work...! Experience a secret office romance with a slightly sadistic older junior.

This is the physical copy of the Twenty and the Beast manhwa.